Simon Waller, Digital Content Editor

You may not want to hear it, but shoppers should already be planning for Christmas if they want to avoid ending the year in debt, analysts have warned.

Today, September 17, marks 99 days to 25 December, with research from American Express suggesting one in seven has already started buying gifts.

While that kind of planning might seem far too meticulous for most, breaking Christmas costs into more affordable monthly chunks could help shoppers avoid trouble later on.

The Money Advice Service found that more than six million Britons fell behind on their finances in January this year as excessive festive season spending caught up with them.

Standard Life's Julie Hutchison offers five tips:

1. Start saving now

Start putting money aside now - for example, £20 a week - and you will have much more available for Christmas shopping. Physically putting this money aside can really help, as some people find they spend more unknowingly when it is in their bank account.

With the typical family Christmas costing £650, a little extra saved each week will help tremendously come December. Setting aside £20 a week between now and the end of November would give you an extra £300 towards this.

2. Book your travel well in advance

Whether you are booking a hotel, train journey or flight, doing so in advance could really cut your costs. Make sure you shop around for different prices - there are lots of websites which can help you do this, such as TrainLine and CheapFlights.

3. Put price limits on presents

Make sure you sit down with family and friends to discuss the subject of presents sooner rather than later. Why not agree to do a Secret Santa within your friendship group rather than buying individual gifts and set a price limit for family presents?

Setting a maximum price is an effective way to help factor in present costs, making it easier to plan.

4. Shop smart

Bear affordability in mind when shopping, especially when it comes to the big Christmas food shop. Can you bulk-buy at a discount supermarket? Does your local butcher or food shop offer a savings scheme to help you spread the cost through the year?

If you are buying for young children they will be unaware of price so there is little point going overboard with top-of-the-range gifts. Similarly, if you know someone has simple tastes, do not opt for designer gear if they would be happy with a more basic version.

5. Use social media to bag a bargain

Use Twitter to scan popular phrases and hashtags such as #deal or #offer - you will find many people sharing extra tips or links to discount vouchers and special offers.

It is also worth following big brands and retailers as many regularly announce deals and offers available through their social channels. ASOS, M&S and Amazon are great examples of brands that reward loyal customers with discount codes and early entry to sales.